CN114694193A - Sensing device and operation method thereof - Google Patents
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Abstract
The invention provides a sensing device and an operation method thereof. The sensing device includes a plurality of light sensing columns. The light sensing columns are sequentially scanned according to a scanning frequency. The light sensing array is provided with a plurality of light sensing circuits. The optical sensing circuit receives a sensing starting signal, a writing signal and a sensing power supply signal. The light sensing circuit generates a light sensing result based on the sensing power signal according to the sensing starting signal and the writing signal. The sensing power supply signal is sequentially switched between a first voltage and a second voltage according to the scanning frequency. The first voltage is different from the second voltage.
Description
Technical Field
The present invention relates to a sensing device and an operating method thereof, and more particularly, to a sensing device for sensing a fingerprint and improving the quality of the fingerprint image and an operating method thereof.
Background
Fingerprint identification belongs to a biometric identification technology, and is divided into a plurality of fingerprint identification technologies according to a sensing mode, wherein the fingerprint identification technologies include optical fingerprint identification, capacitive fingerprint identification and the like. The current optical fingerprint identification can be applied to the fingerprint identification under the screen so as to realize the fingerprint identification function on the display. However, the currently applied devices are limited by the circuit layout and the differences between the circuit elements, which causes the odd-even phenomenon in the fingerprint image and affects the image quality.
Disclosure of Invention
The invention provides a sensing device which can improve the quality of fingerprint imaging.
The sensing device of the invention comprises a plurality of light sensing columns. The plurality of light sensing columns are sequentially scanned according to a scanning frequency. Each light sensing row is provided with a plurality of light sensing circuits. Each optical sensing circuit receives a sensing starting signal, a writing signal and a sensing power supply signal. Each light sensing circuit generates a light sensing result based on the sensing power signal according to the sensing starting signal and the writing signal. The sensing power supply signal is sequentially switched between a first voltage and a second voltage according to the scanning frequency. The first voltage is different from the second voltage.
The invention also provides an operation method of the sensing device. The operation method comprises the following operations: scanning a plurality of light sensing columns in sequence according to a scanning frequency, wherein each light sensing column is provided with a plurality of light sensing circuits; enabling each light sensing circuit to generate a light sensing result based on the sensing power supply signal according to the sensing starting signal and the writing signal; and switching the sensing power supply signal between the first voltage and the second voltage in sequence according to the scanning frequency. The first voltage is different from the second voltage.
Based on the above, the sensing apparatus and the operating method thereof according to the embodiments of the invention can enable each of the light-sensing circuits to perform corresponding operations according to the scanning frequency by the sensing power signals with different voltages. Therefore, the plurality of light sensing circuits which are located at different layout positions or/and have slight variation can be compensated by the corresponding sensing power signals, so that the same light sensing result is generated to generate the same display effect, and the quality of fingerprint imaging is improved.
In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.
Drawings
FIG. 1 is a schematic diagram of a sensing device according to an embodiment of the invention.
FIG. 2 is a diagram of a light sensing circuit according to the embodiment of FIG. 1.
FIG. 3 is a timing diagram of sensing power signals according to the embodiment of FIG. 1.
Fig. 4A and 4B are schematic diagrams illustrating the operation of the light sensing circuit of fig. 1 according to the embodiment of the invention.
FIG. 5 is a schematic diagram of a sensing device according to an embodiment of the invention.
FIG. 6 is a schematic diagram of a sensing device according to another embodiment of the invention.
FIG. 7 is a schematic diagram of a sensing power signal generator according to the embodiment of the invention in FIG. 6.
FIG. 8 is a schematic diagram of the operation of the sensing power signal generator of FIG. 7 according to the present invention.
FIG. 9 is a diagram illustrating a write signal generator according to the embodiment of the invention shown in FIG. 6.
FIG. 10 is a diagram illustrating operation of the write signal generator according to the embodiment of the invention in FIG. 9.
FIG. 11 is a flow chart of a method of operation of a sensing device in accordance with an embodiment of the present invention.
Description of reference numerals:
100. 500, 600: sensing device
610: substrate
620: driving integrated circuit
630: display area
700_1, 700_2, 700_ n: voltage selector
BUF _1, BUF _2, BUF _3, BUF _ 4: buffer device
DSY: display circuit
FPS (field programmable gate array): light sensing circuit
GL: gate drive signal
GN, GN +1, GN +2, GN +3, GN + 4: time sequence
GNR 1: sensing power supply signal generator
GNR 2: write signal generator
LD: light sensing element
P1, P2: node point
ROW _ D: display column
ROW1, ROW 2: light sensing array
RT1, RT2, RD1, RD 2: time sequence
S1110, S1120, S1130: step (ii) of
SCN1, SCN 2: scanning signal
SN1, SN 2: time sequence
SOUT1, SOUT 2: light sensing result
SR _1, SR _ 2: shift temporary storage device
SR _ R: sensing an activation signal
SR _ W, SR _ W1, SR _ W2, SR _ W3, SR _ W4: write signal
SVDD, SVDD _1, SVDD _2, SVDD _ n: sensing power supply signals
SVSS: reference signal
SW1, SW 2: control signal
T1, T2: transistor with a metal gate electrode
T3, T4: switch with a switch body
VGH _1, VGH _2, VGL _1, VGL _ 2: voltage of
VH, VL, VGH, VGL: voltage of
Detailed Description
Fig. 1 is a schematic diagram of a sensing device according to an embodiment of the invention, please refer to fig. 1. The sensing device 100 can perform an optical fingerprint recognition function and display a fingerprint image. The sensing device 100 includes a plurality of optical sensing ROWs ROW 1-ROW 2. The light sensing columns ROW1 to ROW2 are sequentially scanned according to a scanning frequency to be driven to perform a light sensing operation.
In the present embodiment, the optical sensing ROWs ROW1 and ROW2 are two adjacent ROWs. The other optical sensing ROWs (not shown) have the same configuration as the optical sensing ROWs ROW1, ROW2, and the optical sensing ROWs ROW1, ROW2 are arranged to form an array. The plurality of light sensing columns respectively correspond to a plurality of odd columns and a plurality of even columns of the fingerprint image according to the arrangement sequence.
Each of the light sensing ROWs ROW1 to ROW2 has a plurality of light sensing circuits FPS. Each photo sensing circuit FPS is configured to receive the corresponding sensing start signal SR _ R, the writing signal SR _ W, the reference signal SVSS and the sensing power signal SVDD. The reference signal SVSS may be a relatively low voltage signal or may be a ground signal. The number of the photo sensing circuits FPS in the present embodiment is only an example, and not limited thereto.
The light sensing circuits FPS located in different light sensing columns ROW 1-ROW 2 may have the same circuit configuration. In each of the light sensing ROWs ROW1 to ROW2 of the present embodiment, the two light sensing circuits FPS share the same sensing power supply signal SVDD. Accordingly, the circuit design of the sensing device 100 can be simplified, thereby improving the platform illumination and process benefits of the sensing device 100.
When performing the photo sensing operation, each photo sensing circuit FPS is configured to generate corresponding photo sensing results SOUT1 and SOUT2 based on the sensing power signal SVDD according to the corresponding sensing start signal SR _ R and the writing signal SR _ W. The sensing power supply signal SVDD is sequentially switched between a first voltage and a second voltage according to a scanning frequency, and the first voltage is different from the second voltage to form a plurality of pulses.
It should be noted that, according to the scanning frequency, the sensing power signals SVDD with different voltages are provided to the corresponding light sensing ROWs ROW1 and ROW2 to compensate the working voltages of the different light sensing circuits FPS in the light sensing ROWs ROW1 and ROW2, so as to generate the same light sensing result SOUT 1. Therefore, under the same light sensing condition, the fingerprint imaging corresponding to the light sensing columns ROW1 and ROW2 can have the same display effect including: e.g. a bright-dark condition, to avoid the odd-even phenomenon in the horizontal direction of the fingerprint imaging. Thus, the sensing device 100 can improve the quality of fingerprint imaging.
FIG. 2 is a schematic diagram of a light sensing circuit according to the embodiment of FIG. 1, please refer to FIG. 2. The photo sensing circuit FPS includes a photo sensing element LD and transistors T1-T2. The anode of the photo sensing device LD is used for receiving the write signal SR _ W, and the cathode of the photo sensing device LD is coupled to the node P1. The control terminal of the transistor T1 is for receiving a sensing start signal SR _ R, the first terminal of the transistor T1 is coupled to the cathode of the photo-sensing element P1 through the node P1, and the second terminal of the transistor T1 is for receiving a reference signal SVSS. The control terminal of the transistor T2 is coupled to the cathode of the photo sensing device LD and the first terminal of the transistor T1 through the node P1, the first terminal of the transistor T2 is used for receiving the sensing power signal SVDD, and the second terminal of the transistor T2 generates the photo sensing result SOUT 1.
FIG. 3 is a timing diagram of sensing power signals according to the embodiment of FIG. 1. In fig. 3, the horizontal axis represents the operation time of the sensing device 100, and the vertical axis represents the voltage value. For details of the operation of sensing the power supply signal SVDD, please refer to fig. 1 and fig. 3. During the time sequence GN to the time sequence GN +4, the plurality of light sensing columns ROW1 to ROW2 are sequentially scanned, and the sensing power signal SVDD is a voltage VH or a voltage VL according to the scanning frequency to be provided to the corresponding light sensing columns ROW1 to ROW2, respectively.
For example, at timing GN +1, the light sensing column ROW1 is scanned, and the sensing power signal SVDD is the voltage VH. At timing GN +2, the light sensing column ROW2 is scanned, the sensing power signal SVDD is voltage VL, and so on. In other words, when the odd photo sensor arrays and the even photo sensor arrays are scanned in sequence, the sensing power supply signal SVDD is sequentially switched between the voltages VH and VL.
FIGS. 4A and 4B are schematic diagrams illustrating the operation of the photo-sensing circuit of FIG. 1 according to the present invention. In fig. 4A and 4B, the horizontal axis represents the operation time of the sensing device 100, and the vertical axis represents the voltage value. For details of the operation of performing the light sensing by the light sensing circuit FPS of the light sensing ROW1, please refer to fig. 1 and fig. 4A simultaneously. For details of the operation of performing the light sensing by the light sensing circuit FPS of the light sensing ROW2, please refer to fig. 1 and fig. 4B simultaneously.
In fig. 4A, at timing RT1, the light sensing circuit FPS is reset. At this time, the sensing start signal SR _ R is at a logic high level to turn on the transistor T1, and the write signal SR _ W is at a relatively low voltage to turn off the photo sensing device LD. At this time, the residual charge of the photo sensing device LD and the voltage at the node P1 can be reset to the voltage value of the reference signal SVSS, for example, equal to the ground signal, through the transistor T1.
At timing SN1, the photo sensing circuit FPS senses a photo signal. At this time, the sensing start signal SR _ R is at a logic low level to turn off the transistor T1, and the write signal SR _ W is maintained at a low voltage level. At this time, the light sensing element LD may sense an external light signal.
At the time sequence RD1, the light sensing circuit FPS reads the light signal. At this time, the sensing start signal SR _ R is maintained at a logic low level to turn off the transistor T1, and the write signal SR _ W is pulled high to turn on the photo sensing device LD. And causes the light sensing element LD to pull up the sensing signal on node P1. The sensing power supply signal SVDD is supplied to the transistor T2. The transistor T2 is turned on according to the sensing signal at the node P1, and generates a light sensing result SOUT1 based on the sensing power signal SVDD.
After a period of time, the photo sensing circuit FPS repeatedly performs the reset, sensing and reading operations at timings RT2, SN2 and RD2, which are not described herein.
In fig. 4B, the operation of performing the light sensing by the light sensing circuit FPS of the light sensing ROW2 is the same as that described above with respect to the embodiment of fig. 4A, and is not repeated herein. The difference from the embodiment of FIG. 4A is that the voltage at node P2 is different from the voltage at node P1. Since the parasitic capacitance and/or the connection resistance in the different photo sensing circuits FPS have slight differences, the voltages at the nodes P1 and P2 are different during the reading operation.
It should be noted that, since the sensing power signal SVDD has different voltages (e.g., the voltages VH and VL shown in fig. 3) at different timings to sequentially drive the corresponding light display columns ROW 1-ROW 2, the voltage of the sensing power signal SVDD can compensate for the voltage difference at the nodes P1 and P2, respectively.
In the present embodiment, the voltage value of the first voltage (e.g., voltage VH) of the sensing power supply signal SVDD is related to the equivalent capacitance on the node P1, and the voltage value of the second voltage (e.g., voltage VL) of the sensing power supply signal SVDD is related to the equivalent capacitance on the node P2. For example, in the light-sensing column ROW1, since the voltage at the node P1 is low, the sensing power signal SVDD provided to the light-sensing column ROW1 is a high voltage (e.g., voltage VH) to increase the voltage of the light-sensing result SOUT 1. In the light-sensing column ROW2, the voltage at the node P2 is higher, and the sensing power signal SVDD provided to the light-sensing column ROW2 is a low voltage (e.g., voltage VL) to lower the voltage of the light-sensing result SOUT 1. Therefore, the sensing power signal SVDD can reversely compensate the voltage difference of the photo sensing results SOUT1 in the adjacent two light display ROWs ROW 1-ROW 2 by alternately switching the high voltage and the low voltage, so that the corresponding fingerprint images have the same display effect.
Fig. 5 is a schematic diagram of a sensing device according to an embodiment of the invention, please refer to fig. 5. The difference from the embodiment of fig. 1 is that the sensing device 500 further includes a display column ROW _ D, and the display column ROW _ D is disposed adjacent to the light sensing column ROW 1. The display ROW _ D has a plurality of display circuits DSY for displaying images according to the gate driving signals GL. In the present embodiment, the number of the display circuits DSY corresponds to the number of the photo sensing circuits FPS, but not limited thereto.
In the present embodiment, the sensing power signal SVDD is directly supplied by the driving circuit of the driving sensing device 500, and thus no other generating circuit is needed to generate the sensing power signal SVDD.
Fig. 6 is a schematic diagram of a sensing device according to another embodiment of the invention, please refer to fig. 6. In this embodiment, the sensing device 600 includes a substrate 610, a driving integrated circuit 620, a display area 630, and a sensing power signal generator GNR 1. The difference from the embodiment of fig. 5 is that the sensing power signal is generated by the sensing power signal generator GNR1 according to the driving signal of the driving integrated circuit 620.
The driving integrated circuit 620, the display area 630 and the sensing power signal generator GNR1 are disposed on the substrate 610. In the top view, the display area 630 is disposed in the central region of the substrate 610, the driving ic 620 is disposed on the short side of the peripheral region of the substrate 610, and the sensing power signal generator GNR1 is disposed between the display area 630 and the driving ic 620. In other embodiments, the sensing power signal generator GNR1 may be disposed below the display region 630 or integrated in the driving integrated circuit 620.
The driving integrated circuit 620 is used for driving circuits in the display area 630 to display images and/or sense fingerprints, and is used for driving the sensing power signal generator GNR1 to generate sensing power signals. The display region 630 may be a display panel having a fingerprint recognition function. The sensing device 100 of fig. 1 or the sensing device 500 of fig. 5 may be disposed in the display region 630.
FIG. 7 is a schematic diagram of the sensing power signal generator according to the embodiment of the invention shown in FIG. 6, please refer to FIG. 7. The sensing power signal generator GNR1 is coupled to the photo sensing circuits and is used for generating sensing power signals SVDD _1 to SVDD _ n to the photo sensing circuits located in different columns. The sensing power signal generator GNR1 can stagger the sensing power signals SVDD _1 to SVDD _ n to be equal to the voltage VH and the voltage VL according to the scanning sequence of the photo sensing rows.
The sensing power signal generator GNR1 includes a plurality of voltage selectors 700_1 ~ 700_ n. Each of the voltage selectors 700_ 1-700 _ n selects the output voltage VH or VL according to the control signals SW 1-SW 2 to generate the corresponding sensing power signals SVDD _ 1-SVDD _ n.
Each of the voltage selectors 700_ 1-700 _ n may have the same circuit configuration and include switches T3-T4. Taking the voltage selector 700_1 as an example, the switch T3 is controlled by the control signal SW 2. The first terminal of the switch T3 is used for receiving the voltage VH, and the second terminal of the switch T3 is used for outputting the voltage VH to generate the sensing power signal SVDD _ 1. Switch T4 is controlled by control signal SW 1. The first terminal of the switch T4 is for receiving the voltage VL, and the second terminal of the switch T4 is for outputting the voltage VL to generate the sensing power signal SVDD _ 1.
The number of the voltage selectors 700_ 1-700 _ n is at least equal to 2, and there is no fixed upper limit. The number of the voltage selectors 700_1 to 700_ n and the corresponding sensing power signals SVDD _1 to SVDD _ n in the present embodiment is only an example and not limited thereto.
FIG. 8 is a schematic diagram of the operation of the sensing power signal generator of FIG. 7 according to the present invention. In fig. 8, the horizontal axis represents the operation time of the sensing power signal generator GNR1, and the vertical axis represents the voltage value. The voltage selector 700_1 is taken as an example to illustrate the operation details, please refer to fig. 7 and fig. 8. At timing GN +1, the control signal SW1 is logic low to turn off the switch T4, and the control signal SW2 is logic high to turn on the switch T3 to output the voltage VH. At timing GN +2, the control signal SW1 is logic high to turn on the switch T4, and the control signal SW2 is logic low to turn off the switch T3 to output the voltage VL. The continued timings GN +3 GN +4 repeat the operations of the timings GN +1 GN +2, and so on to generate the sensing power signal SVDD _ 1.
The control signals SW1 and SW2 are pulse signals and may be inverted signals with respect to each other. In some embodiments, the control signals SW1 and SW2 are determined according to a scanning order of the light sensing rows.
Referring back to fig. 6, in some embodiments, the sensing device 600 further includes a write signal generator GNR 2. The write signal generator GNR2 is disposed on the substrate 610. In the top view, the write signal generator GNR2 is disposed on one or both sides of the long side of the peripheral region of the substrate 610. The write signal generator GNR2 is used to generate a write signal for the photo sensing array. The write-in signal is a pulse signal, and the pulse heights corresponding to two adjacent light sensing rows are different.
FIG. 9 is a diagram illustrating a write signal generator according to the embodiment of the invention shown in FIG. 6, please refer to FIG. 9. The write signal generator GNR2 includes a plurality of shift registers SR _1 SR _2 and a plurality of buffers BUF _1 BUF _ 4. One shift register SR _1 SR _2 is configured with two buffers BUF _1 BUF _4 to generate corresponding scan signals SCN1 SCN 2. The buffers BUF _ 1-BUF _4 are used for outputting the voltages VGH _1 or VGH _2 and the voltages VGL _1 or VGL _2 based on the voltages VGH _ 1-VGH _2 and the voltages VGL _ 1-VGL _2 according to the scan signals SCN 1-SCN 2 to generate the write signals SR _ W1-SR _ W4.
The shift registers SR _1 SR _2 may be any type of shift register known to one skilled in the art, and are not limited in any way.
In the present embodiment, the voltage VGH _1 has a first pulse height (low voltage value) different from a second pulse height (high voltage value) of the voltage VGH _ 2. The voltages VGL _1 and VGL _2 may have the same voltage value. In addition, voltages VGH _1 and VGL _1 can correspond to odd columns of photo sensing columns, so that the corresponding write signals SR _ W1 and SR _ W3 have pulses with low voltage values. Similarly, voltages VGH _2 and VGL _2 can correspond to even columns of photo sensing columns, such that the corresponding write signals SR _ W2 and SR _ W4 have different pulses than the write signals SR _ W1 and SR _ W3.
FIG. 10 is a diagram illustrating operation of the write signal generator according to the embodiment of the invention in FIG. 9. In fig. 10, the horizontal axis represents the operation time of the write signal generator GNR2, and the vertical axis represents the voltage value. For details of the operation of the write signal generator GNR2, please refer to fig. 9 and fig. 10. The buffer BUF _1 outputs a voltage VGH _1 at a first timing according to the scan signal SCN1 to generate a write signal SR _ W1 of a first photo sensing column. The buffer BUF _2 outputs the voltage VGH _2 at the second timing according to the scan signal SCN1 to generate the write signal SR _ W2 for the second photo sensing column. Similarly, the buffers BUF _3 and BUF _4 respectively output the voltage VGH _1 and the voltage VGH _2 at corresponding timings according to the scan signal SCN2 to generate the write signal SR _ W3 for the third photo sensing column and the write signal SR _ W4 for the fourth photo sensing column.
The first and third photo sensing columns can be odd columns, and the pulses of the corresponding write signals SR _ W1 and SR _ W3 have the same voltage value VGH _ 1. Similarly, the second and fourth photo sensing columns can be even columns, and the pulses of the corresponding write signals SR _ W2 and SR _ W4 have the same voltage value VGH _ 2.
It should be noted that the voltage values VGH _1 and VGH _2 are related to the equivalent capacitance of the photo sensing circuit for reversely compensating the corresponding voltage difference between two adjacent photo sensing rows, so as to make the corresponding fingerprint images have the same display effect under the same photo sensing condition.
It should be noted that the voltage pulse signals with different magnitudes generated by the write signal generator GNR2 can compensate for the difference of the photo sensing results generated by different photo sensing rows, so as to improve the quality of the fingerprint image. In addition, the write signal generator GNR2 can also increase the flexibility of voltage matching adjustment for the photo-sensing result.
Fig. 11 is a flowchart of an operation method of a sensing device according to an embodiment of the invention, please refer to fig. 11. The method of operation may include the following steps. First, a plurality of photo sensing columns are sequentially scanned according to a scanning frequency, wherein each photo sensing column has a plurality of photo sensing circuits (step S1110). Referring to the embodiment of fig. 1, the optical sensing ROWs may be optical sensing ROWs ROW 1-ROW 2, and the optical sensing circuit may be an optical sensing circuit FPS. Next, each photo sensing circuit generates a photo sensing result based on the sensing power signal according to the sensing start signal and the write signal (step S1120). Referring to the embodiment of fig. 1, the sensing start signal, the writing signal and the sensing power signal may be the sensing start signal SR _ R, the writing signal SR _ W and the sensing power signal SVDD, respectively, and the light sensing result may be the light sensing result SOUT 1. Then, the sensing power signal is sequentially switched between the first voltage and the second voltage according to the scanning frequency (step S1130). Referring to the embodiment of fig. 3, the sensing power signal SVDD is sequentially switched between the voltage VH and the voltage VL according to the scan frequency.
The details of the above steps have been described in the foregoing examples and several embodiments, and are not repeated herein.
In summary, in the sensing device and the operating method thereof according to the embodiments of the invention, the sensing device provides different voltages to the corresponding photo sensing rows by using the sensing power signal, so as to compensate for variations of different photo sensing circuits, so that each photo sensing circuit outputs the same photo sensing result and has the same fingerprint imaging effect. In some embodiments, the sensing device utilizes write signals provided at different voltage pulse heights to corresponding photo sensing rows, which not only compensates for variations of different photo sensing circuits, but also increases flexibility in circuit design.
Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.
Claims (18)
1. A sensing device, comprising:
a plurality of photo-sensing arrays, which are scanned in sequence according to a scanning frequency, wherein each photo-sensing array has a plurality of photo-sensing circuits, each photo-sensing circuit receives a sensing start signal, a write signal and a sensing power signal,
each light sensing circuit generates a light sensing result based on the sensing power signal according to the sensing starting signal and the writing signal, and the sensing power signal is switched between a first voltage and a second voltage in sequence according to the scanning frequency, wherein the first voltage is different from the second voltage.
2. The sensing device as claimed in claim 1, wherein the photo sensing circuits commonly receive the sensing power signal, the photo sensing rows include at least one first photo sensing row and at least one second photo sensing row adjacent to the first photo sensing row, the sensing power signal is the first voltage when the at least one first photo sensing row is scanned, and the sensing power signal is the second voltage when the at least one second photo sensing row is scanned.
3. A sensing apparatus as claimed in claim 2, wherein each of the light sensing circuits comprises:
a light sensing element having a first end for receiving the write signal;
a first transistor having a control terminal for receiving the sensing start signal, a first terminal coupled to the second terminal of the optical sensing device, and a second terminal for receiving a reference signal; and
a second transistor having a control terminal coupled to the second terminal of the photo sensing device, wherein the first terminal of the second transistor receives the sensing power signal and the second terminal of the second transistor generates the photo sensing result.
4. The sensing apparatus as claimed in claim 3, wherein a voltage value of the first voltage is related to an equivalent capacitance at the control terminal of the second transistor of each of the photo-sensing circuits on the at least one first photo-sensing row, and a voltage value of the second voltage is related to an equivalent capacitance at the control terminal of the second transistor of each of the photo-sensing circuits on the at least one second photo-sensing row.
5. The sensing device of claim 2, further comprising:
and a sensing power signal generator for alternately equalizing the sensing power signal to the first voltage and the second voltage according to the scanning sequence of the at least one first light sensing row and the at least one second light sensing row.
6. The sensing apparatus of claim 5, wherein the sensing power signal generator comprises:
and each voltage selector selects and outputs the first voltage or the second voltage according to a control signal to generate the sensing power supply signal corresponding to each light sensing circuit.
7. The sensing device as claimed in claim 6, wherein the control signal is determined according to a scanning sequence of the at least one first row of light sensors and the at least one second row of light sensors.
8. The sensing device as claimed in claim 6, wherein each of the voltage selectors comprises:
a first switch having a first end receiving the first voltage, a second end generating the sensing power signal corresponding to each of the photo sensing circuits, the first switch being controlled by the control signal; and
a second switch having a first end receiving the second voltage, a second end generating the sensing power signal corresponding to each of the photo sensing circuits, the second switch being controlled by the reverse direction of the control signal.
9. The sensing device of claim 5, further comprising:
a write signal generator for generating the write signal corresponding to each photo sensing row,
the writing signal is a pulse signal, and the pulse height of the writing signal corresponding to the at least one first optical sensing row is different from the pulse height of the writing signal corresponding to the at least one second optical sensing row.
10. The sensing apparatus of claim 9, wherein the write signal generator comprises:
a plurality of shift registers, each shift register is used for generating a scanning signal corresponding to each light sensing row; and
a plurality of buffers, each of which outputs a third voltage or a fourth voltage based on a third voltage and a fourth voltage according to the corresponding scanning signal to generate the writing signal corresponding to each of the photo sensing circuits,
the third voltage is different from the fourth voltage and is respectively related to the equivalent capacitance of each light sensing circuit on the at least one first light sensing row and the at least one second light sensing row.
11. A method of operation of a sensing device, comprising:
scanning a plurality of light sensing arrays in sequence according to a scanning frequency, wherein each light sensing array is provided with a plurality of light sensing circuits;
enabling each light sensing circuit to generate a light sensing result based on a sensing power supply signal according to a sensing starting signal and a writing signal; and
the sensing power supply signal is switched between a first voltage and a second voltage in sequence according to the scanning frequency, wherein the first voltage is different from the second voltage.
12. The method of operation of claim 11, further comprising:
enabling the light sensing circuits to receive the sensing power supply signal together, wherein the light sensing rows comprise at least one first light sensing row and at least one adjacent second light sensing row;
when the at least one first light sensing row is scanned, the sensing power signal is the first voltage; and
when the at least one second photo sensing row is scanned, the sensing power signal is the second voltage.
13. The method of claim 12, wherein the first voltage is related to an equivalent capacitance of each of the photo sensing circuits on the at least one first photo sensing row, and the second voltage is related to an equivalent capacitance of each of the photo sensing circuits on the at least one second photo sensing row.
14. The method of operation of claim 12, further comprising:
providing a sensing power signal generator to make the sensing power signal alternately equal to the first voltage and the second voltage according to the scanning sequence of the at least one first light sensing row and the at least one second light sensing row.
15. The method of operation of claim 14, further comprising:
and a plurality of voltage selectors of the sensing power signal generator selectively output the first voltage or the second voltage according to a control signal to generate the sensing power signal corresponding to each optical sensing circuit.
16. The method of operation of claim 15, further comprising:
the control signal is determined according to the scanning sequence of the at least one first light sensing row and the at least one second light sensing row.
17. The method of operation of claim 14, further comprising:
providing a write signal generator to generate the write signal corresponding to each photo sensing row,
the writing signals are pulse signals, and the pulse height of the writing signal corresponding to the at least one first optical sensing row is different from the pulse height of the writing signal corresponding to the at least one second optical sensing row.
18. The operating method according to claim 17, wherein the step of providing the write signal generator to generate the write signal corresponding to each of the photo sensing rows comprises:
providing a plurality of shift registers to generate a scanning signal corresponding to each photo sensing row; and
providing a plurality of buffers to output a third voltage or a fourth voltage to generate the write signal corresponding to each of the photosensitive circuits according to the corresponding scan signal,
the third voltage is different from the fourth voltage and is respectively related to the equivalent capacitance of each light sensing circuit on the at least one first light sensing row and the at least one second light sensing row.
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